33 



Molhiscu — 1. Casts of a TeUina allied to T. bipUcata, a miocene 

 fossil, and of another near T. lusoria. 2. Cast of a Cytherea resem- 

 bling C. Sayana, Conrad. 3. Three casts of a Mya, one of which 

 bears a close resemblance to Mya truncata. 



Mr. Lyell concludes, from the various evidence here given, that 

 the strata of Martha's Vineyard are miocene. The numerous re- 

 mains of Cetacea of the genera Balcena and Hyperoodon are adverse 

 to the supposition of their being Eocene, while such fossils abound 

 in the miocene beds of America. The other fossils all point to a 

 similar conclusion. 



Letter from J. Hamilton Cooper, Esq., to Charles Lyell, Esq., 

 V.P.G.S., " On Fossil bones found in digging the New Brunswick 

 Canal in Georgia." 



Mr. Cooper prefaces his communication by a description of the 

 country surrounding the locality in which the bones were found. 

 The portion described is that part of the sea-coast of Georgia which 

 lies between the Alatamaha and Turtle rivers in one direction, and 

 the Atlantic Ocean and the head of tide water on the other. For 

 twenty miles inland the land is low, averaging a height of from ten 

 to twenty feet, and reaching, in some instances, forty feet, and con- 

 sisting of swamps, salt-marshes, sandy land, and clay loam. It then 

 suddenly rises to the height of seventy feet, and runs back west at 

 this elevation about twenty miles, at which point there is a similar 

 elevation of between sixty and seventy feet. The whole of this 

 district is a post-tertiary formation, and is composed of recent allu- 

 vium, and a well-characterized marine post-pliocene deposit. The 

 recent alluvium is divided into inland- swamp, tide- swamp, and salt- 

 marsh. The two last occupy a shallow basin having a depth of about 

 twelve feet, the bottom and sides of which are the post-pliocene for- 

 mation. This the author divides into three groups, in the last of 

 which, constituting the elevated sand hills, no organic remains have 

 been found; in the two former marine shells of existing species 

 occur. 



The fossil bones of the land mammalia discovered by Mr. Cooper, 

 were found resting on the yellow sand and enveloped in the recent 

 clay alluvium. Their unworn state and the grouping together of 

 many bones of the same skeleton, render it highly probable that the 

 carcasses of the animals falling or floating into a former lake or 

 stream, sank to the sandy bottom, and were gradually covered to 

 their present depth by the sedimentary deposits from the water. 

 Among them were remains of the megatherium. Mastodon giganteum, 

 mammoth, hippopotamus and horse. The fossil shells found in the 

 post-pliocene, were species at present existing on the neighbouring 

 shores. 



The facts narrated by Mr. Cooper lead to the following conclu- 

 sions : — 1st. That the post-pliocene formation extends further south 

 than Maryland, to which it has hitherto been limited. 2nd. The co- 

 existence of the megatherium with the mammoth, mastodon, horse, 

 bison, and hippopotamus. 3rd, That the surface of the country has 



VOL. IV. PART I. D 



